The present invention disclosed herein relates to a current controlling device and an electric field emission system including the same.
An electric field emission device includes a cathode where an electric field emitting source (an emitter) emitting electrons is formed. When an electric field is applied to the cathode of the field emission device, the electrons emitted from the emitter are attracted to an anode. The electric field applied to the cathode is determined by an anode voltage in a dipole structure, or a gate voltage in a three-pole structure.
For stable driving, a current flowing through the electric field emission device is required to be constantly controlled. There is a method of controlling a voltage applied to the electric field emission device in order to control the current of the field emission device. However, the current of the electric field emission device increases exponentially in response to the applied voltage. Also, since a characteristic of the emitter of the electric field emission device may be degraded or activated over time, a current emitted for an identical voltage may decrease or increase. Accordingly, it is typically difficult to control an electric field emission current to be constant by using a voltage applied to an electric field emission device. For stable driving of the electric field emission device, a technique is required to control the field emission current to be constant without controlling an applied voltage.